diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 6e6b6a11b3ced64d1c90e3c9d35d25823f6b5ccf..b75d9fb2fa91d4ed2481841e4eff3f68f4503e31 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -39,6 +39,19 @@ bool iommu_found(void) } EXPORT_SYMBOL_GPL(iommu_found); +/** + * iommu_set_fault_handler() - set a fault handler for an iommu domain + * @domain: iommu domain + * @handler: fault handler + */ +void iommu_set_fault_handler(struct iommu_domain *domain, + iommu_fault_handler_t handler) +{ + BUG_ON(!domain); + + domain->handler = handler; +} + struct iommu_domain *iommu_domain_alloc(void) { struct iommu_domain *domain; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 9940319d6f9d3ab0d1442a5fa31a7db9be6dafa3..d084e8777e0ef629b4ef2de8830f0a0d8a90c239 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -26,9 +26,18 @@ #define IOMMU_CACHE (4) /* DMA cache coherency */ struct device; +struct iommu_domain; + +/* iommu fault flags */ +#define IOMMU_FAULT_READ 0x0 +#define IOMMU_FAULT_WRITE 0x1 + +typedef int (*iommu_fault_handler_t)(struct iommu_domain *, + struct device *, unsigned long, int); struct iommu_domain { void *priv; + iommu_fault_handler_t handler; }; #define IOMMU_CAP_CACHE_COHERENCY 0x1 @@ -67,6 +76,43 @@ extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, unsigned long iova); extern int iommu_domain_has_cap(struct iommu_domain *domain, unsigned long cap); +extern void iommu_set_fault_handler(struct iommu_domain *domain, + iommu_fault_handler_t handler); + +/** + * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework + * @domain: the iommu domain where the fault has happened + * @dev: the device where the fault has happened + * @iova: the faulting address + * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...) + * + * This function should be called by the low-level IOMMU implementations + * whenever IOMMU faults happen, to allow high-level users, that are + * interested in such events, to know about them. + * + * This event may be useful for several possible use cases: + * - mere logging of the event + * - dynamic TLB/PTE loading + * - if restarting of the faulting device is required + * + * Returns 0 on success and an appropriate error code otherwise (if dynamic + * PTE/TLB loading will one day be supported, implementations will be able + * to tell whether it succeeded or not according to this return value). + */ +static inline int report_iommu_fault(struct iommu_domain *domain, + struct device *dev, unsigned long iova, int flags) +{ + int ret = 0; + + /* + * if upper layers showed interest and installed a fault handler, + * invoke it. + */ + if (domain->handler) + ret = domain->handler(domain, dev, iova, flags); + + return ret; +} #else /* CONFIG_IOMMU_API */ @@ -123,6 +169,11 @@ static inline int domain_has_cap(struct iommu_domain *domain, return 0; } +static inline void iommu_set_fault_handler(struct iommu_domain *domain, + iommu_fault_handler_t handler) +{ +} + #endif /* CONFIG_IOMMU_API */ #endif /* __LINUX_IOMMU_H */